How to add and delete Values from List Of Values?

Dear All,

We need to add values on Tax ID Type field in Customer Form, navigation is => Brokerage and Forwarding -->  Customer Management --> Customer. Here field in Tax Information Tab is Tax ID Type list which contains DUNS, EIN and some other fields so we need  to add some new fields in it and delete some of them. So please help us to understand that how to achieve this as we are on 6.3.4.1 Cloud.

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